SDL: Add support for loading PNG images
SDL: Make text_osd_render reusable
SDL: Add the ability to render OSD images
SDL: Set a minimum window size
SDL: Don't use "emulating" in the sound driver
SDL: Reformat the main loop
SDL: Prevent expired timers from triggering
SDL: Start refactoring to allow different modes
ALL: Documentation fixes
SDL: Modularize quit
SDL: Turn the renderable list into a tree
SDL: SDLmain has disappeared on my system
SDL: Allow renderables to be aligned relatively to their parent